As you have proven to yourself from the slurry test, the pH of the liquid doesn't change the pH of the media. The media changes the pH of the liquid within an hour.
I Ain't Afraid Of No Ghost - Seedsman's Purple Ghost Candy Comparative Grow SIP/SCROG
- Thread starter Ke0ncp
- Start date
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- #262
Hahah you are correct sir!!
And I mis spoke. It was sulfur I added last time.
Ok time to amend some of that and do a top watering. It’s pretty clear that I need to do that.
SmokinRasta
Well-Known Member
To me it looks like a nitrogen deficiency that might be cause by ph or excess of salts or other elements.... so keeping an eye on the nutes and the ph might help. My nutes supplier, CANNA, says ph for soil 5.8-6.2, but I usually stay with my 6.5 at feeding without any problems.
I think you got to much through CalMag, Epson salt and other nutes - maybe you should recheck the concentrations.
Since I use my MONO Mg I don't even have to use any CalMag. But thats what helps on my side...
I think you got to much through CalMag, Epson salt and other nutes - maybe you should recheck the concentrations.
Since I use my MONO Mg I don't even have to use any CalMag. But thats what helps on my side...
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- #264
Ok this is from a google search that led me to another place.
“1/3 of a cup aluminum sulfate to lower the soils pH from pH 7.6 to pH 6.5. It takes roughly 1.0666 tablespoons to lower the pH by pH 0.2 in a (5 gallon pot)”
So if I’m aiming for 5.7 and using an online calculator I see that 1.0666 tbsp = 8.34g
So here is my stoned math!
6.4 (current ph) - 5.7 (ph goal) = .7
.7 divided by .2 = 3.5
3.5 * 8.34gr = 29.19 grams to lower my ph to 5.7
Does this make any sense lol
“1/3 of a cup aluminum sulfate to lower the soils pH from pH 7.6 to pH 6.5. It takes roughly 1.0666 tablespoons to lower the pH by pH 0.2 in a (5 gallon pot)”
So if I’m aiming for 5.7 and using an online calculator I see that 1.0666 tbsp = 8.34g
So here is my stoned math!
6.4 (current ph) - 5.7 (ph goal) = .7
.7 divided by .2 = 3.5
3.5 * 8.34gr = 29.19 grams to lower my ph to 5.7
Does this make any sense lol
Is aluminum sulfate what you have? Also, I'm unclear why they're using the 7.6 and 6.5 numbers if it's just 1.0666 Tbs to lower it 0.2 points generally. Also also, is 1.0666 Tbs (how does anyone measure that?) actually 8.34g of your sulfur?
I'd see if you can get similar numbers elsewhere to confirm their info.
That said, the math looks good but I'm not sure I would do it all at once, or at least not on both pots at the same time.
I'd see if you can get similar numbers elsewhere to confirm their info.
That said, the math looks good but I'm not sure I would do it all at once, or at least not on both pots at the same time.
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- #266
I’m ROLLING THE DICE hahaha lol
I read through my last grow, was a good reminder, and found I’m having the same exact issue hahaha. I have to chalk it up to the ph of the media as all other inputs have been measured and calculated for gradual increases in small increments.
If this works I now have a measured amount to amend into the rest of my grows using this bale of promix. If it kills my ladies then I will need to reevaluate my grow medi/nute combo to see what direction I need to go.
Though I think that I’m am on the right track and that “think” is really a hope hahahaha. It was the sulfur last time that I think helped them turn the corner. Fortunately this time, I have time to correct it before flipping
Here is to lush green plants in 14 days time
I read through my last grow, was a good reminder, and found I’m having the same exact issue hahaha. I have to chalk it up to the ph of the media as all other inputs have been measured and calculated for gradual increases in small increments.
If this works I now have a measured amount to amend into the rest of my grows using this bale of promix. If it kills my ladies then I will need to reevaluate my grow medi/nute combo to see what direction I need to go.
Though I think that I’m am on the right track and that “think” is really a hope hahahaha. It was the sulfur last time that I think helped them turn the corner. Fortunately this time, I have time to correct it before flipping
Here is to lush green plants in 14 days time
- Thread starter
- #268
Ahahaha!! We will see won’t we
I think I’m on the right track though and thanks again for all of the help!
SmokinRasta
Well-Known Member
I love this attitude! Learning by doing/ trying... - best way to make experiences!
...guess I don't have to tell you, but if I rember right alumminum sulfat works vs molybdenum and this vs Nitrogen... - so might not be the best choise in your situtation imo
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- #270
This hurts my brain haha.
So sulfur vs nitrogen?
As it stands I might need to add some N to my nutes.
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- #271
Day 49 - Veg Day 29 of 48ish:
Man o man what a roller coaster this grow has been so far. Started off super easy and then WHAM!! Slapped in the face with problems, and what’s embarrassing is that it is the SAME exact problems I’ve had on previous grows. Soooo hopefully this time I’ve actually learned something??? The jury is still out on that one and don’t ask my wife as she has a quick answer….
So here we are mid-veg with these fine ladies and I’m finding myself riddled with an issue, well with the help of you fine people, I think it’s comes down to a batch of ProMix that isn’t buffering correctly, my local water makeup, and my nutes having a good supply of calcium with a calcium rich water.
Soo both plants have been amended with sulfur to help lower the ph of the promix, I have backed my nutes down to 4.5 for the moment and I am also adding in 1gr/gal of Epsom salt to boost the Mg without adding any additional Cal.
So what’s different this time from last time and only to get the same results??
Last grow I was not monitoring DLI or VPD and I did not have the best nute schedule, as far as weekly increases goes. I added sulfur mid grow, adjust my lights based on DLI, and started ph down my water.
This grow I have been pretty strict with maintaining a weekly increase in DLI, VPD, and Nutes, I also started ph down from the beginning this grow as this was one of the things that helped me “fix” it last time.
So the only conclusion I can draw is that this batch of promix is off and the addition of the sulfur last time was the fix. The other changes may have helped, or maybe they didn’t on the last grow, but every thing else minus my city water and the addition of sulfur I think was pretty on point. The addition of Epsom this time will be an added bonus over last grow and I’m also going to boost the potassium once we hit flower.
Time will tell in the next 2 weeks time if this theory is correct.
There is also the possibility that I switch to RO water that way I can take the constant unknown of where my water actually falls in the range that my city has posted. This will also help keep my Ca more in range of where it should be.
So onto this weeks updated numbers.
DLI from 40 to 45
VPD from .9 to 1.0
I ended up adding in that @ViparSpectra XS1500pro into the tent, raising all the lights up in the tent and I’m getting a great spread of light across the entire 4x4 footprint. Should work out great!
Well I think that’s about it and in case you don’t know. I ain’t afraid of no ghost???
Man o man what a roller coaster this grow has been so far. Started off super easy and then WHAM!! Slapped in the face with problems, and what’s embarrassing is that it is the SAME exact problems I’ve had on previous grows. Soooo hopefully this time I’ve actually learned something??? The jury is still out on that one and don’t ask my wife as she has a quick answer….
So here we are mid-veg with these fine ladies and I’m finding myself riddled with an issue, well with the help of you fine people, I think it’s comes down to a batch of ProMix that isn’t buffering correctly, my local water makeup, and my nutes having a good supply of calcium with a calcium rich water.
Soo both plants have been amended with sulfur to help lower the ph of the promix, I have backed my nutes down to 4.5 for the moment and I am also adding in 1gr/gal of Epsom salt to boost the Mg without adding any additional Cal.
So what’s different this time from last time and only to get the same results??
Last grow I was not monitoring DLI or VPD and I did not have the best nute schedule, as far as weekly increases goes. I added sulfur mid grow, adjust my lights based on DLI, and started ph down my water.
This grow I have been pretty strict with maintaining a weekly increase in DLI, VPD, and Nutes, I also started ph down from the beginning this grow as this was one of the things that helped me “fix” it last time.
So the only conclusion I can draw is that this batch of promix is off and the addition of the sulfur last time was the fix. The other changes may have helped, or maybe they didn’t on the last grow, but every thing else minus my city water and the addition of sulfur I think was pretty on point. The addition of Epsom this time will be an added bonus over last grow and I’m also going to boost the potassium once we hit flower.
Time will tell in the next 2 weeks time if this theory is correct.
There is also the possibility that I switch to RO water that way I can take the constant unknown of where my water actually falls in the range that my city has posted. This will also help keep my Ca more in range of where it should be.
So onto this weeks updated numbers.
DLI from 40 to 45
VPD from .9 to 1.0
I ended up adding in that @ViparSpectra XS1500pro into the tent, raising all the lights up in the tent and I’m getting a great spread of light across the entire 4x4 footprint. Should work out great!
Well I think that’s about it and in case you don’t know. I ain’t afraid of no ghost???
I hope you, your sulfur, your RO water, and your math get this thing headed in the right direction: 
- Thread starter
- #273
We will see
Thanks again for all of the help there Master Shredder err Master Shed! Haha
Thanks again for all of the help there Master Shredder err Master Shed! Haha
g-one-three
Well-Known Member
I know that you've probably already looked and posted to it but by chance did you see they reopened the Mega Crop thread now that they are a sponsor again? I'm wondering if maybe there is someone with similar issues, and hopefully solutions buried in that thread lol
Either way I'm sending good vibes to you and your girls
Either way I'm sending good vibes to you and your girls
- Thread starter
- #275
I did see that! I took a sneak at it and didn’t see anything right off the bat but I need to dig around in there a little more.I know that you've probably already looked and posted to it but by chance did you see they reopened the Mega Crop thread now that they are a sponsor again? I'm wondering if maybe there is someone with similar issues, and hopefully solutions buried in that thread lol
Either way I'm sending good vibes to you and your girls
MedScientist
Well-Known Member
WooHoo!
In the beginning, I thouht they were just Hungry. It's hard to tell the True colors assuming you take pics with the lights on.
You have been presenting with signs of Overwatering, but not in the Normal way I see in SIP's. I can't find any info on light height, intensity, canopy temps, humidity, air flow or pests to determine what is causing the low transpiration. But I suspect that it is environmental because the problems present differently from top to middle and bottom.
The low N, Cal def, brown crumbly leaves, crinkled leaves, bloated leaves, saggy look, leaf edges turning under, and now the browning leaf edges, confirm to me that Overwatering (root/O2) IS the original problem.
Then all the additives are just complicating things? If MG is supposed to be a stand alone nute program, I would eliminate the additives you are using to chase symptoms, but not dealing with the cause.
The plants are only showing slightly high ph, but not enough to be causing these problems. Which Do seem to get worse after each feeding?
Once you figure out the Cause of the low transpiration/root O2 problem and correct it, they should get back to their normal routine!
In the beginning, I thouht they were just Hungry. It's hard to tell the True colors assuming you take pics with the lights on.
You have been presenting with signs of Overwatering, but not in the Normal way I see in SIP's. I can't find any info on light height, intensity, canopy temps, humidity, air flow or pests to determine what is causing the low transpiration. But I suspect that it is environmental because the problems present differently from top to middle and bottom.
The low N, Cal def, brown crumbly leaves, crinkled leaves, bloated leaves, saggy look, leaf edges turning under, and now the browning leaf edges, confirm to me that Overwatering (root/O2) IS the original problem.
Then all the additives are just complicating things? If MG is supposed to be a stand alone nute program, I would eliminate the additives you are using to chase symptoms, but not dealing with the cause.
The plants are only showing slightly high ph, but not enough to be causing these problems. Which Do seem to get worse after each feeding?
Once you figure out the Cause of the low transpiration/root O2 problem and correct it, they should get back to their normal routine!
- Thread starter
- #277
Good point on the light height as I’ve not really put much thought into it other than ensuring I hit my DLI weekly goals. At first I thought closer lights with lower power levels would be better. However it was pointed out to me that higher up in the tent with more power to hit my DLI goal would give better light penetration through the canopy.
As it stands now the lights are probably 2’ above the lights and at my DLI goal of 45. Which is 75% of 2 200w lights and 25% of a 150w light. This last light was just added yesterday.
I have 1 4” intake fan and 1 4” exhaust fan set up to keep the VPD at my weekly goals, I also have a humidifier in there to help keep VPD in line.
I also have 4 6” circulating fans in there. 3 of them are cruising across the top/into the plants and 1 of them is blowing across the top of the SIPs.
As it stands now with a VPD goal of 1 my temp is 76.4°, humidity is 60.5% and VPD is 1.01.
Last 24 hour avg
Temp 81.6, humidity 65.2% and VPD was 1.02
The last 7 days:
Temp 80.6, humidity 67.5, VPD was .94 to a goal of .90 for last week. The plants weeks start on Tuesday.
I have a small space heater to control temps and had it set at 80° until a few days ago I turned it down to 76°, I think that’s what I put it at.
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- #278
I was thinking about this on the drive into work and forgot to mention that the intake, output fans, and the humidifier are all controlled by an ACI 69Pro and set to control VPD.
In there I have the minimum for the intake set at 0 so it’s off unless the VPD gets too low, then it ramps up accordingly. However, I also have the maximum set at 7 out of 10 for it to keep a consistent negative pressure in the tent. This is in efforts of keeping the stank down
For the exhaust fan, the minimum is set to 1 to keep that fan always pulling old air out and then just like the intake it ramps up accordingly when the VPD gets too low. It goes up to full power depending on the current VPD reading.
I have the sensor right at the top of the canopy to try and get the most accurate canopy reading as I can. I guess I should probably check the difference in temperature between the actual leaves and the sensor, there is a spot in the controller to set this.
The other thought I had was maybe I should increase the ratio between intake and exhaust from 0/1 to 1/3 respectively to increase overall new air?
Though I will say last run, I did not have the ability to control VPD at all. I was running an inkbird for humidity and temp and was set at 75° and 60%rh all through veg and my fans were running at 25% for intake and 50 - 65% for exhaust and I had the same problems. Which is why think that it’s the media ph being the major problem.
I am open to all suggestions to help improve my environmental settings though
In there I have the minimum for the intake set at 0 so it’s off unless the VPD gets too low, then it ramps up accordingly. However, I also have the maximum set at 7 out of 10 for it to keep a consistent negative pressure in the tent. This is in efforts of keeping the stank down
For the exhaust fan, the minimum is set to 1 to keep that fan always pulling old air out and then just like the intake it ramps up accordingly when the VPD gets too low. It goes up to full power depending on the current VPD reading.
I have the sensor right at the top of the canopy to try and get the most accurate canopy reading as I can. I guess I should probably check the difference in temperature between the actual leaves and the sensor, there is a spot in the controller to set this.
The other thought I had was maybe I should increase the ratio between intake and exhaust from 0/1 to 1/3 respectively to increase overall new air?
Though I will say last run, I did not have the ability to control VPD at all. I was running an inkbird for humidity and temp and was set at 75° and 60%rh all through veg and my fans were running at 25% for intake and 50 - 65% for exhaust and I had the same problems. Which is why think that it’s the media ph being the major problem.
I am open to all suggestions to help improve my environmental settings though
MedScientist
Well-Known Member
WooHoo!
Great Details!
Although, VPD is a great tool to dial things in, I would probably abandon that until you get the environment correct, then dial it in to fine tune it.
Not being there in person, I have to make alot of assumptions, so Please correct anything I misunderstood!
A few things jump out at me, and I would to discuss for your consideration BEFORE you make any changes.
I ran into problems in my tent from too much negative pressure. If the tent walls are being sucked in, it is probably too much. I didn't use an intake fan, but solved it by opening all the vents. I Believe too much negative pressure affects how the water moves thru the plant.
Instead of having your fans blow accross and downward into the canopy, I prefer to lower them to blow across and upward to push the heat away from the tops. To increase evaporation, you could also use one to blow upward thru your plants.
Under normal circumstances, your Humidity may be ok. But your plants are too wet, figuratively speaking. I would lower it.
I am curious to see what the temp and humidity would be if you disconnect the humidifier and heater? Raising the lights at higher percentage was a great idea! Does that provide adequate heat in the tent without need for the heater?
There is also the possibility that your Perched Water Table is too high in the SIPS. Increasing the the air zone between the upper medium and res by watering less, but more often could help.
Twisted fan leaves is a sign that ph is high,, and I could only see a few in your pcs. So I don't think that is a major factor to what is going on. Most all of the things showing points to Incorrect water movement thru the plants.
To summarize my thoughts...
Tent pressure, Humidity, PWT and fan placement are things I would tweak first. I Believe the right combination of tweaks would do your plants Well!
Great Details!
Although, VPD is a great tool to dial things in, I would probably abandon that until you get the environment correct, then dial it in to fine tune it.
Not being there in person, I have to make alot of assumptions, so Please correct anything I misunderstood!
A few things jump out at me, and I would
to discuss for your consideration BEFORE you make any changes. I ran into problems in my tent from too much negative pressure. If the tent walls are being sucked in, it is probably too much. I didn't use an intake fan, but solved it by opening all the vents. I Believe too much negative pressure affects how the water moves thru the plant.
Instead of having your fans blow accross and downward into the canopy, I prefer to lower them to blow across and upward to push the heat away from the tops. To increase evaporation, you could also use one to blow upward thru your plants.
Under normal circumstances, your Humidity may be ok. But your plants are too wet, figuratively speaking. I would lower it.
I am curious to see what the temp and humidity would be if you disconnect the humidifier and heater? Raising the lights at higher percentage was a great idea! Does that provide adequate heat in the tent without need for the heater?
There is also the possibility that your Perched Water Table is too high in the SIPS. Increasing the the air zone between the upper medium and res by watering less, but more often could help.
Twisted fan leaves is a sign that ph is high,, and I could only see a few in your pcs. So I don't think that is a major factor to what is going on. Most all of the things showing points to Incorrect water movement thru the plants.
To summarize my thoughts...
Tent pressure, Humidity, PWT and fan placement are things I would tweak first. I Believe the right combination of tweaks would do your plants Well!
- Thread starter
- #280
First off, thanks for your input! And great points. Let me see if I can provide any additional details or information.
Humidifier kicks on throughout the day and night.
I can probably ditch the humidifier at this point and soon the dehumidifier will go in.
I let the reservoirs go fully or damn near fully empty before I fill them again to try and avoid that. I wonder if I should go a full 24hrs or more of empty to promote sucking the media dry?
Thanks again for the input! No ego here so you won’t hurt my feelings
Understood. I have have often wondered/ thought that I could achieve my target VPD numbers with a wide range of various environments so long as there was the correct temperature to humidity ratios.
Fully get that.
My tent walls are most certainly sucked in but not dramatically so.
This is not a bad idea. Currently the 3 blowing across the canopy are blowing down across it. I can easily move the fans around so that they are blowing up through the canopy. I will probably make that change this afternoon actually.
Here is the current snapshot of what it looks like with lights on. Day time temp I’m 87° night time I’m 76° and the only time the heater comes on is at night.
Humidifier kicks on throughout the day and night.
I can probably ditch the humidifier at this point and soon the dehumidifier will go in.
I let the reservoirs go fully or damn near fully empty before I fill them again to try and avoid that. I wonder if I should go a full 24hrs or more of empty to promote sucking the media dry?
Thanks again for the input! No ego here so you won’t hurt my feelings
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